142 ROBERT D. VAN VALIN, JR.
Only in (129a) is the subordinate clause a direct daughter of the clause node
modified by the IF operator; therefore by (111) it is in the PFD, and
accordingly táku can be interpreted as a WH-word in a WH-question. In
(129b) there is no relationship between the relative clause and the matrix
clause node, because the subordinate clause is NP-internal. Here two con
siderations come into play: first, the constraint in (111), and second, the fact
that NP is a basic information unit whose internal elements cannot be ques
tioned by a simple question word like who or what (see section 5.4.2.2).
Finally, in (129c) the subordinate clause is an adjunct modifier of the core,
and, as in Figures 36 and 38 for English, it is not a direct daughter of the clause
node modified by the IF operator.
Thus, in order to form a question in which the WH-word functions as
an element in a subordinate clause, the subordinate clause must be in the
PFD, and this is determined (at least in part) by the principle in (111). This
is relatively easy to see in languages like Lakhota, in which WH-words
appear in situ, but this has been obscured in languages like English in which
WH-words occur in the clause-initial PCS. Because these restrictions were
first discovered in languages with WH-word displacement (Ross 1967), it
has been assumed that the explanation of these restrictions must make cru
cial reference to the "movement" of the WH-words, but languages like
Lakhota show that this is not in fact the case. An account based on move
ment like subjacency is not extendable to Lakhota and other such WH-
situ languages in a straightforward way; in order to make it work, move
ment in abstract representations like Logical Form must be posited (see
Huang 1981). In contrast, the explanation proposed here for the restrictions
in Lakhota can be extended without modification to languages like English.
The comparable English constructions to (129b,c) in Lakhota are given as
the ungrammatical glosses, What did the man see the dog which bit?" and
What did the man's wife bring him water, while he was eating?, and they
are ruled out by the same principles as their Lakhota counterparts. WH-
questions out of relative clauses are precluded by both principle (111), since
the relative clause is not a direct daughter of the clause node modified by
the IF operator, and by the fact that the WH-word is part of the internal
structure of a basic information unit, NP (see Figure 40). The adverbial
subordinate clause would have the same structure as in Figures 36 and 38, and
again the same two considerations come into play: on the one hand, the
subordinate clause is not a direct daughter of the matrix clause node, and
on the other, the WH-word is part of the internal structure of a basic infor-